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There are a few reports on Twitter (http://bit.ly/10rc69">http://bit.ly/10rc69, but some right after WWDC that are not currently appearing in search results) that Snow Leopard has dramatically increased battery life. I'm curious to see how much of an impact it will have on real-life battery results (let alone marketing claims) come September. Reply

Windows 7 should be better in terms of Battery Performance actually. They rewrote the kernel and scheduler for Windows 7 to let the CPU reach deeper sleep states which was impossible due to interrupts occurring every 8 ms or so.
Could you try to bench Win7 with some more going on like watching DVD? According to MS it should perform better then. Also Vista SP2 may behave differently from SP1 in terms of battery performance. Reply

i was just wondering if the tests for windows was done by booting on windows, or by using VMware fusion or parallels? if you're just emulating windows, will that have an effect on battery life?

so it seems that by using windows, you'll have a higher power consumption? so is it safe to say, that the mac mini which was advertised to idle at 13W will have an increase in power consumption while running windows?
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I think the reason why Mac OSX is fairing better in battery life is because the way it uses its resources. I am using a my Macbook right now Aand I noticed that if I open 10 browsers, Only the browser that is currently on the top screen is getting worked on. anything that I've minimized will be left alone, so less cpu cycles are being used. I know this for a fact because if I upload pictures on flickr and i minimize the browser it doesn't upload till the screen is on. Just the workload i guess. Windows always have something running in the background while OSX seems to halt programs I've noticed. Mind you I'm not a techie so I am not qualified to assess anything. This is just something I've noticed when using my stuff. Reply

If patterns repeat themselves Anand, shouldn't we expect a big update on the MacBook Pro in October? In your recommendation should I wait to buy until October for a faster Intel chip or is this Summer update stellar?? Reply

I would take a pc laptop, your lenovo, for example, and install osx on it (assumeing it was compatible enough). It would be interesting to see if the opposite is true. maybe since the lenovo vista battery life is better than the mbp in vista, its osx life would also be better than the mbp. Reply

On my netbook, I got about 30mins less battery life out of Ubuntu 8.10 LPIA version than Windows XP when browsing the net wirelessly. Much of this was due to the lack of power saving features in the drivers for things like audio, WLAN etc. Also CPU usage was generally higher and stayed at 100% more of the time. Of course, it might not be the same with full featured laptops, but I have a feeling Linux is no more efficient than Windows due to the poor driver support. Reply

It depends entirely on the driver support for your hardware and whether you compile the kernel yourself or whether you just use whatever some distro provides. With excellent manufacturer driver support and a self-compiled kernel, one should be able to obtain better battery life in linux than Windows XP. I mean, OS X IS based on freebsd, which is very similar to linux. Reply

I know this is not what this article was about but I bought the MacBook Pro 17" back in March. I have been pretty pleased with it except for one thing. I find that even the shorter battery life under Vista is still very good life as I get about 4-5 hours on my battery under email and web surfing conditions. However, I do have one problem in Vista 64 Bit, I consistantly have lockups, this started after about 3-4 weeks of no problems. Under OS X I have yet to have a lock up so I am pretty sure it is a driver. It gets worse as time goes on. I believe it is a NIC (wireless most likely) issue and am wondering if anyone else has experianced this and if you were able to resolve it. Currently I am trying to isolate it by disabling the wireless controller under Vista. Any help from the Anandtech crew would be helpful. Reply

Would it be possible if the reason OS X has longer battery life compared to Vista was because of Apple "capped" the HD bandwith through software at 1.5Gb/s while Vista and Windows 7 are both running at 3.0Gb/s? Reply

Perhaps there are legal issues with doing this, but for curiousity's sake, perhaps installing OSX on a "windows" notebook and testing to see if that causes it to have a longer battery life than running windows will determine if OSX uses less power or if OSX has hardware specific trickery going on to make the battery last longer. Reply

Stupid thought, but have you considered, almost just for giggles, running your battery bench in a VM'ed copy of windows?

Most likely the battery life will be even lower..... but there's an ever so slight chance that os x is doing something tricky under the hood, and if so your battery life could increase. Even staying the same could be an indicator, with the VM overhead and such. Reply

One reason Vista MAY have a shorter battery life is Microsoft's business model of backward compatibility. As I understand it, in order for MS to support the multitude of old software on it's new operating systems, MS codes and tests specifically for legacy applications. For example, if you want to run the original SIMS on Vista, the OS detects that SIMS is running and performs code specifically so that SIMS works.

The need for specific handling is two fold. The original OS function calls may not have behaved exactly as per the spec, so application developers coded for the actual behaviour provided by the OS. On the flip side, application developers may have developed code that functioned correctly, but were misusing the intended purpose of the OS function calls.

I remember reading that when Vista development was running late, that over 95% of the Vista code base was dedicated to supporting backward compatibility and that it was the biggest cause for delivery delay and restriction of functionality.

If my understanding is correct, then for any given call to the OS, a number of checks are being run for legacy software even when running current applications. This is a backward compatibility tax that we all pay, all the time. With every new release of MS operating system, this problem gets bigger and more complex, requiring more resources at design, code, test and run time. This MAY explain why battery life has reduced in Windows 7 more than Vista, which is intern worse than XP.

Apple reduces these problems in two ways. Firstly, they occasionally break backward compatibility support (e.g. OS-9 to OS-X in 2002). Also, their licensing and testing model for third party applications reduces the amount of "bad but functioning" applications that misuse the OS function calls.

Mind you, I'm not criticising MS for their backward compatibility support. It's what consumers and business have demanded from them and has made them very successful. It's just that the backward compatibility support back to DOS days has a cost for all of us, including MS.
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Among the many flaws of Vista, and a major reason it was never widely adopted, is the fact that it wasn't backward compatible. I did buy a Vista laptop, but when fewer than half my applications would run on it, I returned it and bought an XP system. Try not making excuses for Micro$oft. They're a multi-billion dollar big boy and can defend themselves. When Micro$oft releases their new buggier, incompatible, operating systems we should instead ask 1)What does this offer thats worth the upfront cost, the time to install it, the time to install all my applications, 2) the cost to replace all my expensive applications that no longer work, 3) the time to find, purchase, and install all the applications that no longer work, 3) the time to learn yet another buggy and unintuitive interface, 4) the cost of new hardware and lower productiviity due to the poorer performance of the bloated and underperforming OS. 5) Does this OS perform the basic functions of an OS well such as disk storage management - Micro$oft has yet to get Windows explorer to work well.

The conclusion is that Micro$oft is not backward compatible, and their self-serving goal of making money hand over fist clashes with my desire for value for my money. Reply

Interesting you think I'm defending MS. I'm not an MS fan. Far from it. In fact, after working as a developer for 20 years, MS was one of the big reasons I recently threw in the towel and have jumped ship into a brand new career, starting with 4 years back in University.

However, about Vista backwards compatibility... I'm not surprised not everything worked for you. On the whole, I imagine MS got quite a lot of things to work, but frankly they don't have a chance of getting all the 3rd party apps AND hardware combinations to work all the time. The permutations and combinations of the problem they are trying to solve is patently ridiculous beyond belief. Trying to get it to work is just silly and believing they can do it is gullible.

Having worked as a master engineer developing telecoms network software for the major firm in the indudtry for over 7 years, I've seen the rod built for it's back by one company where that company controlled every application and every hardware release. In addition, the required quality of all the releases was far beyond a consumer ALT-CTRL-DEL OS like Windows. The problems we had with backward compatibility were enormous. I think MS has NO chance, they don't control all the parts and don't have access to majority of application code or hardware designs. Frankly I think it's futile, BUT, we all expect it of them and they keep promising it. Reply

What software didn't work? Pretty much everything I had running on XP ran in Vista. I say pretty much, because, while I can't think of a single program that didn't run, it's been over 2 years since I installed Vista.

I don't run Industrial CADD/CAM software, so that might be it, but those programs were always problematic with an OS change. They are typically certified on a specific hardware/software combo. Other than that, Vista was (I run Win 7 RC at the moment) amazingly backwards compatible as well as stable. After SP1, even better. The "Vista is teh suxor" FUD is getting real old now.

One of the things that annoys me more than almost anything else about Vista on my desktop machine (on which I also run XP sometimes) is its incessant churning of the hard drive -- I don't know what it has to do so much with the hard drive, but it annoys the hell out of me. Does it do this on laptops as well? That would be a sure way to kill the battery life. Reply

I consistently get 4-4.5 hrs of wifi browsing with my X300 (6-cell battery, 6 mo. old, 99% of original battery capacity according to thinkpad Power Manager). Not though that I do use mainly Opera+Flashblock, which might factor into it. Vista SP1 and SP2 both have the same battery life for me. Then again, I've also implemented several SSD tweaks such as turning off Indexing and Superfetch, both of which should trim power usage. Reply

Apple has not done a good job of keeping the Vista drivers up to date. I'm using the Snow Leopard Boot Camp beta drivers with Windows 7 and they are much better. My gues is that you will have to upgrade to Snow Leopard to get netter Boot camp drivers. Reply

SSD depends on NCQ to keep a smooth flow of commands in order to maximise performance and efficiency. Without SATA2 there is no NCQ so who is to say that these high performance SSD will even be able to reach their rated performance let alone hit the SATA1 bottleneck?

Besides, the SATA link has overheads in the region of 5% to 10% so the cap comes at around 130MB/s not 150. I think some 7200rpm disks will be very close to this limit. Reply

Except that SSDs do not use NCQ the way HDDs do therefore your entire argument is pointless. I think the performance specs given by manufacturers for their SSDs rely on NCQ to keep the SSD controller fed with enough instructions in order to achieve said performance.

there only way to prove it is to test on SATA and SATA2 but from the little I have read on SSDs, the NCQ is actually important for them. Reply

Okay, I'm having a hard time understanding you. I think you meant to say that SATA-I doesn't have NCQ. You're wrong in that case, as the 925X SATA-I chipset does support NCQ, and does show a notable difference in benchmark. The NCQ support does not drop just because it's an SSD.

Maybe you mean to say that "the NCQ is actually important for {SSDs}", which I completely agree with.

I'm confused by your statement that "SSDs do not use NCQ the way HDDs do." What exactly do you mean? Are you referring to the mechanical aspect of most-efficient path of an HDD versus the command queue of an SSD? That somehow the gains made by always having a task queued is different between them, and having SATA-II fixes this?

The biggest bottle-neck for these laptops isn't the SATA-I interface taking out precious literal seconds from their productivity, it's all the hours of whining.

For the moment the Sata 1,5 Gbps speed issue is not that crucial.
In order to be able to take advantage of a faster read capability than 1.5 Gbps you have to be able to write the data to somewhere else with the same speed. Sure there is SSDs which sequential write speed exceeds 1,5 Gbps but not that many nor they do it that much faster than 1.5 Gbps. Not to mention that there isn't any HDD anywhere near this kind of write speeds.

Having said that I still have to wonder why Apple is doing this. It seems so pointless to cause all the BS around this issue for nothing. Not to mention that in the (near) future this "problem" has to be taken care of as the SSD technology takes it's giant leaps. AND like said it is already today possible to find and put in SSDs to your notebook that will take a hit from a too slow Sata interface. Reply

The difference between Windows and OS X could IMHO be partially explained by their different schedulers. A quanta based scheduler like in Windows has to keep at least one core running. In OS X it would in theory be possible to sleep until next interrupt. I doubt this is the actual reason for most of the difference, but it is quite possible OS X really has an architectural edge when it comes to power efficiency.

As for the SATA issue, it is a non-issue. While it is possible to install a drive that can read faster than that, it is infeasible to install anything to a laptop that actually uses data faster than that on a sustained and significantly frequent basis. There are some video and signal processing applications that can do it, but only a complete moron would run them on a laptop or indeed anything without significantly more RAM than any consumer level laptop can support. Reply

It WAS only infeasible because laptop HDD performance was so lacking. What else can benefit? How about booting? Saving to hiberfile. Loading a game.

It is untrue that there aren't constant gains, disk I/O is one of the biggest bottlenecks in typical laptop use. I'm not suggesting it wouldn't run great with the same SSD in SATA150 mode, but if you're paying a premium you should at least get something premium for the money. Reply

Apparently someone (MacRumours, I believe) is reporting that Macs shipped with the built-to-order SSD option are seeing 3.0 Gbps on the SATA interface.

This is all very shady, but it sounds like someone should be able to find the switch to flip (whether it's in firmware or what) to gain 3.0 Gbps mode for those of us upgrading the internal drive to an SSD. Reply

As far as I can tell, it is literally impossible to get Vista to stop using the disk long enough for it to spin down. Turn off every non-critical service, kill Explorer and every application, and the core OS and required services will still touch the disk once or twice a second.

If OSX can actually sit still for a moment and be happy with what it has in RAM, that may contribute to the different battery performance on the same hardware. Reply

Yes, but what about XP? You can easily make the hard drive spin down under XP, yet older reviews comparing Macs under XP and OSX show similar results.

When idle, a Macbook with a full Core2 CPU running OSX uses about as much power as an Atom netbook running XP. No PC laptop running any version of Windows comes close. Got to give credit where credit is due, Apple has really done a great job optimizing the whole platform (OS and hardware) for fantastic battery life. Either that, or Microsoft and its partners have done a horrible job. Reply

I originally guessed that this was done intentionally to maximize battery life but since 3Gb/s is baked into the 9400m would this still cut power draw? I suspect that this is still the case as I highly doubt it was an accident and there is no evidence I'm aware of pointing to an OS/Driver bug. While this will limit top speeds I doubt that the user experience will be affected perceptibly. Reply

You can manually choose Vista power saving option. When forced on maximum power saving, the laptop should run at SpeedStep freq. You guys need to do that test again by forced power saving under vista and see how long it runs this time. Reply

Except that people pay more for higher SSD performance (SSDs performing beyond 150MB/s cost more than those that don't, and better random I/O also translates into more frequent peaks above 150) so if they don't get that they will want to pay less or receive a refund. Reply

iTunes gets terrible performance in Windows. If that is part of your tests, it's not going to be a fair fight. Something lightweight (like Winamp Lite) or something native (like WMP) would be a better apples-to-apples comparison.

It's sort of like running a non-native application inside a emulator and expecting the performance/effeciency to be the same.

//waiting for some fanboy to try and use this test as "evidence" that OSX is better than Windows...

//awesome battery power, way to go apple!
//still dont like the non-removable battery. Proprietary 5 point screws to ensure you dont change the battery..tsk, tsk.

//my Dell XPS M1710 can barely get through a 2 hour movie before the battery dies...it's a desktop replacement, so I have no problem running it on a wire. Reply

The SATA 1.5Gbps issue on the new 13" and 15" Macbook Pro is even more SEVERE than expected.
(The 17" Macbook Pro, white 13" Macbook, and 13" Macbook Air all have SATA 3.0Gbps so are not affected.)

I'm not sure about all the variables in play here, but for whatever reason (perhaps due to different points of overhead and/or controller architecture) people using fast SSDs on the new Macbook Pro 13" and 15" are seeing them bottlenecked at far less than 150MB/sec.

Here are some preliminary results for sequential read and write speeds from a new 15" Macbook Pro versus the older using an OCZ 120GB Vertex:

Bottom line, if this is a hardware problem that can't be corrected by firmware, Apple REALLY SCREWED UP. Although you'll still get the benefits of fast random access in the OS and applicaitons, The SATA I in the new 13"/15" MB Pro will cause an enormous performance degradation when copying large files or transferring large files to and from external drives --- on the order of losing >50% of your throughput! Reply

How is this going to limit any transfers to or from an external drive? The fastest external interface on these machines is the 800 Mbps Firewire (1394b) interface. That is way below (after subtracting overhead) the 115 MBps and 95 Mbps maximum you give. Thus I don't see any reduction in the read/write to an external drive let alone the >50% you claim. Reply

External devices aren't the problem; the problem is internal SATA drives running at half their designed bandwidth. That said, how much file copying (i.e. sequential transfers) do you do on a regular basis? Even if those situations are half as fast as they could be (and they're more like 60-70% as fast), I don't think I copy large files around on my HDD much at all, and if you only have a single HDD it's mostly a non-issue. Still doesn't make sense, though. Reply

This is the base $1699 model, there's no 9600M unfortunately. The results echo what I've seen in the past with OS X vs. Vista, it's just nice to have an update. Hopefully we can get a real response from Microsoft this time.

Wow, that is a shame. I was looking at purchasing one of these (first saving) for school. It would be nice to go ~7 hours without a charger on campus. I suspect most of the tools I use are Windows only though (I am almost certain).

There is a real lack of good Windows PCs in the market. Nothing with battery life near as good, or a body construction out of one nice block of metal. My piece of crap Dell Inspiron 1520 is literally falling apart at this point. I have had 5 repairs on it. I suffered from the faulty 8600M GT, then my motherboard went bad, then my ram went bad, then my LCD flickered, now my casing is getting small cracks....

What is one to do!?! I might just settle for lab computers at this point :( It would be cheaper. Reply

I paid ~1800 for my Inspiron. That is pretty much in line with the MBP. It was one of the first to have the Santa Rosa chipset.

And yes, I would think that Apple Macbook Pros are higher quality, since they use a metal casing and not plastic. Plus innovative battery technologies. I have never owned one though, I could be wrong. They feel nice in the store. Reply

I know that on my 17" Unibody Pro Vista uses the 9600M which does chew up the battery life. Vista support isn't really that great... It took me about a week to get it really stable and even then I still have to attach a mouse to get right clicks to work properly. I didn't think the power usage was just due to the OS, but mainly from the use of the 9600M. Looks like there is even more of a battery tax for using Vista (I currently mostly use OS X, but eventually might do more). Reply